1. Field of Invention
This invention is directed to systems and methods for document distribution and usage authorization of protected documents.
2. Description of Related Art
A sender of a document often wants to ensure that unauthorized access to the document is prevented. The senders have endeavored to add security measures to their documents so that the documents are protected during distribution and usage. Accordingly, only authorized end users can access the protected document.
Document distribution and usage authorization for a protected document may include:
1) An end user as a receiver of protected document contents. For authorization and cryptography purposes, the end user possesses an access device which will engage in the authorized usage.
2) A document processing device, which is a general-purpose computing system such as a PC or a workstation. The protected document is stored and a rendering application is run by the document processing device to process the protected document for the end user.
3) A remote authorization device which acts on behalf of the document owner/distributor to document user authentication, usage authorization and to track document usage.
Protected electronic documents may be secured in electronic envelopes, for example. That is, a content owner/distributor may seal a document in an envelope, and may send the envelope to an end user to open. The envelope is “secured” in that only an intended end user can open the envelope with an access key, for example. Access to a protected document is usually controlled via channels to each end user who wants to view, print, extract, or the like, the protected content, namely, a “high bandwidth” content distribution channel and a “low bandwidth” (secure) key distribution channel. Hence, whether or not the end user is authorized to use the protected document is then controlled mainly by whether or not the end user is allowed to receive the envelope, to possess the right access key to open the envelope, or both.